no, The guy could not find his phone. He used Find my Phone, you added He found his phone.

unless you show me where he said he found the phone. I am guessing eventually he did, or maybe he just remembered where he left it when he was streaming. But assuming what he said was true. "I figured out what was going on and went into the living room to turn off the stereo. Couldn't find the remote in my dazed state so in desperation pulled the plug from the wall." would not have happened, if find my phone helped him find the phone originally, also "Silence. Apart from the dog barking, wife yelling and children crying." means that there was no BEEP BEEP BEEP of Find my phone for him to hear to pin point the phone location after he stopped the audio equipment.

The story might have been a bit different if the phone was plugged into the audio equipment, and so going there to stop the audio equipment would have lead him to find the phone, but airplay means that his phone could be anywhere on the network (i.e. in the home) so the going to the audio equipment is useless.